GEOCHEMICAL CHARACTERISTICS OF THE CAMBRIAN MANGANESE DEPOSITS OF CENTRAL WADI ARABA, JORDAN.
El-Hasan, Tayel (Correspondent author)
Department of Geology, Mu'tah University,61710, AI-Karak - Jordan.
Department of Earth and Environmental Sciences, Hashemite University, Zarqa 13115, P. O. Box 150459, Jordan.
Komuro, Keiso and Kajiwara, Yoshimichi Institute of Geoscience, Univ. of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305 Japan.
Received: 24/2/2001 Accepted:22/9/2001
The petrological and mineralogical investigation of the Cambrian manganese deposits cropping out in Wadi Dana, central Wadi Araba region, reveals that the ore developed through three evolutionary stages: primary, supergene, and epigenetic. Furthermore, the geochemical results show that there is a distinct geochemical signature for each stage. The primary mineralization shows enrichment in a wide spectrum of trace elements, e.g. Cu, Ba, As, Co, Ni, W, Mo, and V, besides Mn and Fe. This is followed by the supergene mineralized horizon that bears enrichment in transitional elements such as Cu, Ba, Ni, Zn, Co, and Pb. Finally, the epigenetic phase which is characterized by higher Pb, Cu, and Zn contents. Moreover, within the supergene horizon Fe/Mn ratio shows a gradual decrease from west to east, indicating deposition under a shallow marine environment. Dramatic increase in Fe/Mn took place at the easternmost site of the basin (Wadi Dabbah) restrictedly, indicating a change in the environment or in the ore formation processes.